Method of casting clad



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METHOD oF CASTING CLAD Filed May 2l, 1958 INVENTOR.

// 4//////////// /fff//V//f//f .United States Patent() n 2,995,816 METHOD F CASTING CLAD James L. Ma, Coatesville, Pa., assignor to Lukens Steel Company, Coatesville, Pa., a corporation of Pennsylvania Filed May 21, 1958, Ser. No. 736,814 8 Claims. (Cl. 29-528) This invention relates to a novel method of casting clad metal.

The principal object of this invention is to reduce the number of method steps used in the process of cladding metal.

Another object of the invention is to produce clad plates by a process which requires but a single rolling operation.

Still another object ofthe invention is to provide a method which will materially reduce the labor involved and at the same time increase the output of clad metal.

Other objects of the invention will appear hereinafter throughout the specication.

rReferring to the drawing:

FIGURE 1 'shows a vertical section through the insert assembly ready for insertion into the mold;

FIGURE 2 shows a vertical section through the mold and the insert located therein;

FIGURE 3 is a vertical section similar to FIGURE 2 after the molten metal forming the backing plates has been poured.

FIGURE 4 is a top plan view of a mold illustrating the inserts supporting elements; and

FIGURE 5 is a vertical section taken substantially along the lines V--V of FIGURE 4.

In carrying out the steps of this method, the insert assembly or pack 2 is prepared by placing a pair of cladding sheets comprising inserts 4 in face to face relation with a layer of parting material 6 between them. The insert assembly 2 is then quickly dipped into a bath of molten steel to precoat the inserts 4 with a layer 8 of steel. The composition of the layer of steel 8 may be of a composition such as that of the base metal. After the inserts have been cooled down to room temperature, the precoated surfaces of the assembly are conditioned by sand or grit blasting, and then the assembly is installed in a suitable mold 10 and the molten metal poured around the assembly to form the backing layers 12 of the plates, as indicated in FIGURE 3. In this operation, the inserts and the molten metal are cast together to form two cast clad metal plates. The use of the parting material between the inserts 4 prevents any union between them with the result that two similar clad plates are produced. After the plates are removed from the mold they are given a single rolling operation.

Any convenient means may be employed to support and locate insert 2 in mold 10, as, for example, that found in Patent No. 1,967,754.

Thus, referring to FIGURES 4 and 5, the mold 10, shown in these figures as a sectional metal mold, may be provided with a number of supports or bridges 14 which lie across the bottom of mold 10 to support the insert Z in spaced relation from the bottom of mold 10. The bridges 14 may be made of metal of the same composition as that which is to be poured into the mold so that they will melt and form part of the ingot. Additional props or supports 16, similar in composition to the bridges 14, may be placed near the top of the mold to hold the insert 2 in place during the pouring operation.

Since no envelope is used to enclose the insert assembly, no welding or other steps used to form the envelope are needed with the resulting saving in labor and material. It has been found that the method of this invention not only results in a saving in labor and material but also 2,995,816 Patented Aug. 15, 1961 ffice in a higher production, due to the fact that there are fewer method steps involved.

v Any suitable parting material may be used to separate the inserts. However, a preferred parting composition is one made up of the following composition:

Ratio by volume:

1 part-Clad Kote (ethyl acetate nitrocellulose) l part-chromium oxide powder (CrzOa).

The insert assembly may be placed in the mold in the usual manner, with or without spacing between the side walls of the mold and the side walls of the insert assembly (not shown). The inserts may be composed of stainless steel, nickel, Monel metal, Inconel metal, or other alloys. The base metal and coating metal are preferably composed of low carbon steels or alloys thereof.

The ethyl acetate and nitrocellulose of the Clad Kote are one to one by volume, and the chromium oxide powder is used in accordance with the Clad Kote" formula.

I'he above description and drawings disclose one embodiment of the invention, and specific language has been employed in describing the figures. It will, nevertheless, be understood that no limitations of the scope of the invention are thereby contemplated, and that various alterations and modications may be made as would occur to one skilled in the art to which the invention relates.

I claim:

l. The method of casting clad metal which comprises placing a parting material between the confronting faces of a pair of inserts, assemblying said inserts into a pack in face to face relation, quick dipping said pack into a bath of molten steel to precoat said inserts with a layer of steel, placing said pack in a mold, and casting the clad by pouring molten metal into the mold around said pack, removing the clad metal from the mold and subjecting the same to a rolling operation.

2. The method of casting clad metal which comprises placing a parting material between the confronting faces of a pair of inserts, assemblying said inserts into a pack in face to face relation, quick dipping said pack into a bath of molten carbon steel to precoat said inserts with a layer of carbon steel, placing said pack in a mold, and casting the clad by pouring molten metal into said mold around said pack, removing the clad metal from the mold and subjecting the same to a rolling operation.

3. The method of casting clad metal which comprises placing a parting material between the confronting faces of a pair of inserts, assemblying said inserts into a pack in face to face relation, quick dipping said pack into a bath of molten steel to precoat said inserts with a layer of steel,.cooling the inserts to room temperature, placing said packing in a mold, casting the clad by pouring molten metal into the mold around said pack, removing said inserts from said mold, and giving them a single rolling operation.

4. 'I'he method of casting clad metal which comprises placing a parting material between the confronting faces of a pair of inserts, assembling said inserts into a pack in face to face relation, quick dipping said pack into a bath of molten steel to precoat said inserts with a layer of steel, cooling the inserts to room temperature, conditioning the precoated surfaces of said inserts by sand blasting, placing said pack in a mold, and casting the clad by pouring molten metal into the mold around said pack, removing the clad metal from the mold and subjecting I the same to a rolling operation.

e 2,995,816 Y Y, e y

in face to face relation, quie-k dipping said pack into a bath of molten steel to precoat said inserts with a layer of steel, placing said pack in a mold, and casting the clad by pouring molten metal into the mold around saidpack, said parting material havingav composition of one parti chromium oxide powder and anv approximatelyn equal part of'a mixture of ethyl acetate and nitrocellulose, removing the clad metal from the mold and subjecting the same to a rolling operation.

y6. The method of casting clad metalwhich comprises Placing a parting material between the confronting faces of a pair of inserts, assembling said inserts into a pack inv face to face relation, quick dipping said packl into a bath of molten steel to precoat said inserts with a layer of steel, placing said pack in a mold, and casting the clad by pouring molten metal of substantially'the same composition as the metal of said molten metal bath into the mold around said pack, removing the clad metal from the mold and subjecting thel same to a rolling operation.

7; The method of casting clad metal which comprises placing a parting material between the confronting faces ofI a pair of inserts, assembling said inserts in a pack in face to face relation, quick dipping said pack into a bath of molten steel to precoat said inserts with a layer of steel, cooling the inserts to room temperature,

conditioning the precoated surfaces of said inserts by sand blasting, placing said pack in a mold, and casting the clad by pouning molten metal of substantially the same composition as the metal of said molten metal bath into the mold around said pack, removing the clad metal from the mold and subjecting the same to a rolling operation.

8. In the manufacture of clad steel, assembling a pack comprisingpra pair of cladding sheets in face to face relationship with parting material interposed therebetween, quick dipping said pack into a bath of molten steel to pre-coat said cladding sheets with a layer of steel, placing said pack in a mold, and pouring molten metal into the mold around the pack to form backing layers for said cladding sheets, removing the clad metal from the mold and subjecting the same to a rolling` operation.

References Cited in the file of this patent UNITED STATES PATENTS Watson et al June 28, 1955 

1. THE METHOD OF CASTING CLAD METAL WHICH COMPRISES PLACING A PARTING MATERIAL BETWEEN THE CONFRONTING FACES OF A PAIR OF INSERTS, ASSEMBLYING SAID INSERTS INTO A PACK IN FACE TO FACE RELATION, QUICK DIPPING SAID PACK INTO A BATH OF MOLTEN STEEL TO PRECOAT SAID INSERTS WITH A LAYER OF STEEL, PLACING SAID PACK IN A MOLD, AND CASTING THE CLAD BY POURING MOLTEN METAL INTO THE MOLD AROUND SAID PACK, REMOVING THE CLAD METAL FROM THE MOLD AND SUBJECTING THE SAME TO A ROLLING OPERATION. 